diff --git a/src/dotnet/FileSystemBase.cs b/src/dotnet/FileSystemBase.cs
index e66da75a..e208abd9 100644
--- a/src/dotnet/FileSystemBase.cs
+++ b/src/dotnet/FileSystemBase.cs
@@ -966,6 +966,49 @@ namespace Fsp
             FileInfo = default(FileInfo);
             return STATUS_INVALID_DEVICE_REQUEST;
         }
+        /// <summary>
+        /// Processes a control code.
+        /// </summary>
+        /// <remarks>
+        /// This function is called when a program uses the DeviceIoControl API.
+        /// </remarks>
+        /// <param name="FileNode">
+        /// The file node of the file or directory to be controled.
+        /// </param>
+        /// <param name="FileDesc">
+        /// The file descriptor of the file or directory to be controled.
+        /// </param>
+        /// <param name="ControlCode">
+        /// The control code for the operation. This code must have a DeviceType with bit
+        /// 0x8000 set and must have a TransferType of METHOD_BUFFERED.
+        /// </param>
+        /// <param name="InputBuffer">
+        /// Pointer to a buffer that contains the input data.
+        /// </param>
+        /// <param name="InputBufferLength">
+        /// Input data length.
+        /// </param>
+        /// <param name="OutputBuffer">
+        ///  Pointer to a buffer that will receive the output data.
+        /// </param>
+        /// <param name="OutputBufferLength">
+        /// Output data length.
+        /// </param>
+        /// <param name="BytesTransferred">
+        /// Receives the actual number of bytes transferred.
+        /// </param>
+        /// <returns>STATUS_SUCCESS or error code.</returns>
+        public virtual Int32 Control(
+            Object FileNode,
+            Object FileDesc,
+            UInt32 ControlCode,
+            IntPtr InputBuffer, UInt32 InputBufferLength,
+            IntPtr OutputBuffer, UInt32 OutputBufferLength,
+            out UInt32 BytesTransferred)
+        {
+            BytesTransferred = default(UInt32);
+            return STATUS_INVALID_DEVICE_REQUEST;
+        }
 
         /* helpers */
         /// <summary>
diff --git a/src/dotnet/FileSystemHost.cs b/src/dotnet/FileSystemHost.cs
index d98ad582..55a14c2c 100644
--- a/src/dotnet/FileSystemHost.cs
+++ b/src/dotnet/FileSystemHost.cs
@@ -1020,6 +1020,35 @@ namespace Fsp
                 return ExceptionHandler(FileSystem, ex);
             }
         }
+        private static Int32 Control(
+            IntPtr FileSystemPtr,
+            ref FullContext FullContext,
+            UInt32 ControlCode,
+            IntPtr InputBuffer, UInt32 InputBufferLength,
+            IntPtr OutputBuffer, UInt32 OutputBufferLength,
+            out UInt32 PBytesTransferred)
+        {
+            FileSystemBase FileSystem = (FileSystemBase)Api.GetUserContext(FileSystemPtr);
+            try
+            {
+                Object FileNode, FileDesc;
+                Api.GetFullContext(ref FullContext, out FileNode, out FileDesc);
+                return FileSystem.Control(
+                    FileNode,
+                    FileDesc,
+                    ControlCode,
+                    InputBuffer,
+                    InputBufferLength,
+                    OutputBuffer,
+                    OutputBufferLength,
+                    out PBytesTransferred);
+            }
+            catch (Exception ex)
+            {
+                PBytesTransferred = default(UInt32);
+                return ExceptionHandler(FileSystem, ex);
+            }
+        }
 
         static FileSystemHost()
         {
@@ -1048,6 +1077,7 @@ namespace Fsp
             _FileSystemInterface.DeleteReparsePoint = DeleteReparsePoint;
             _FileSystemInterface.GetStreamInfo = GetStreamInfo;
             _FileSystemInterface.GetDirInfoByName = GetDirInfoByName;
+            _FileSystemInterface.Control = Control;
 
             _FileSystemInterfacePtr = Marshal.AllocHGlobal(FileSystemInterface.Size);
             Marshal.StructureToPtr(_FileSystemInterface, _FileSystemInterfacePtr, false);
diff --git a/src/dotnet/Interop.cs b/src/dotnet/Interop.cs
index c9a7c95b..c81e9b67 100644
--- a/src/dotnet/Interop.cs
+++ b/src/dotnet/Interop.cs
@@ -457,6 +457,14 @@ namespace Fsp.Interop
                 ref FullContext FullContext,
                 [MarshalAs(UnmanagedType.LPWStr)] String FileName,
                 out DirInfo DirInfo);
+            [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
+            internal delegate Int32 Control(
+                IntPtr FileSystem,
+                ref FullContext FullContext,
+                UInt32 ControlCode,
+                IntPtr InputBuffer, UInt32 InputBufferLength,
+                IntPtr OutputBuffer, UInt32 OutputBufferLength,
+                out UInt32 PBytesTransferred);
         }
 
         internal static int Size = IntPtr.Size * 64;
@@ -486,7 +494,8 @@ namespace Fsp.Interop
         internal Proto.DeleteReparsePoint DeleteReparsePoint;
         internal Proto.GetStreamInfo GetStreamInfo;
         internal Proto.GetDirInfoByName GetDirInfoByName;
-        /* NTSTATUS (*Reserved[39])(); */
+        internal Proto.Control Control;
+        /* NTSTATUS (*Reserved[38])(); */
     }
 
     [SuppressUnmanagedCodeSecurity]